When you throw in the migraine-inducing disputes over Hesychasm, you realize that Athos is a different world indeed.
But it is no monolith today. While Athos has been a pillar of anti-Roman sentiment (sometimes quite deserved, see And All That, 1204), the fact is that the most intractable among them are out of step with the majority, who are loyal to the ecumenically-minded Patriarch Bartholomew, and the confrontations between the two groups have been ugly. In short, when Athos isn't a united bloc, I'm not sure what's left of Weigel's argument.
Yes, there's long way to go before reunion is feasible, but sitting around sighing about the bad Orthodox hating us doesn't serve much purpose.